Abrading tool



W. A. REED ABRADING TOOL Dec. 18, 1934.

Filed Feb. 2l, l93l 2 Sheets-Sheet 1 Dec. 18, 1934. w A REED 1,984,430

ABRADING TOOL Filed Feb. 21, 1931 2 Sheets-Sheet 2 v I MM/ NTUR v ,wMMLMCL {29mg Patented Dec. 18, I934 UNITED STATES PATENT OFFICE William A. Reed, Beverly, Mass., assignor to United Shoe Machinery Corporation, Paterson,

N. J., a corporation of New Jersey Application February 21,1931, Serial No. 517,500

23 Claims. (01. 51-194) This invention relates to abrading tools and is one end of the abrasive cover secured in overherein illustrated as embodied in a shoe-bottomlapping relation to the other end, and a hook scouring roll of the type disclosed in United covered by the overlapping end of the abrasive States Letters Patent No. 1,014,094, granted cover for clamping the overlapped end to the Y January 9, '1912 upon the application of W. A. tool body. The hook which secures the over- 5 Reed. The abrading tool disclosed in the abovelapped end of the abrasive cover is thus kept mentioned patent consists of a tool body adaptout of contactwith the work. In the illustrated ed to be mounted upon a shaft and preferably construction, the overlapping end of the abraprovided with a yieldable periphery to support sive coveris securedindependently of the overan abrasive cover which may consist, for examlapped end, enabling the abrasive cover to be 10 ple, of sandpaper, although abrasive covers havdrawn tightly and thus fitted accurately to the ing cloth bases are frequently employed and the tool body, regardless of any departure of the use of emery and other artificial grits in place tool body from a p fie d a Being thus of sand is common. The abrasive cover is accurately fitted under tension, the abrasive is wrapped about the tool, and its ends are secured 'o vergrips th ool dy ti h ly a all poin to the tool by a c'lamping device which clamps and is thus held by direct frictio al both ends of the abrasive cover simultaneously mentwith the tool body over its entire area to the tool. The clamping device disclosed in a ai h frictional drag of the Work, With the the above-mentioned Letters Patent consists or re ult that n re am n of s r ss is devel- '20 a plurality of clamping members disposed along d at any one Point O the Cove by reason the length of the roll and rovided with mechaf th d a of t w k- Lo al zati n of str ss nism for actuating all of them simultaneously. in the Cover a the points o Clamping,- d e Present day tendencies in the art of shoe r su tendency t a at su p are scouring point to the desirability of using thinth y ini d, While a the a m a y ner sandpaper and abrasives of finer grit, and in Considerable number of Clamping devices to (115- '25 running the roll at higher speeds of rotation, tribute such stress is rendered unnecessary. The thinner the sandpaper and the lighterthe Th s of relatively few clamping dev c s iaglue coating which holds the abrasive material, 01111731368 the attainment of D balance o the greater the degree of flexibility of the sandh flbrading tool at high pe a d it also paper, and the greaterits capacity for yielding minimizes the flattening effect p the y d- 30 readily to the contour of the w k. Thi dable surface of the tool body which results from paper with'fine abrasive material can'be mainthe IOCaHZatiOII of pressure of a large b r tained in relatively steady and continuous enof 30105813! adjacent Clamping d vices. The abragagement with th work with t ibrati or sive cover, which is secured upon the tool in the bouncing of the work. The use of such an abramanner above-described, as in the i1111$- 35 sive covering, especially upon a high-speed roll, trated scouring r011, be ormed with V-shaped results in an improved finish, imparting a uniends which are respectively salient and re-enform soft velvety surface to the work while trant- This form of cov pre ts an advanshortening the time required to perform the op- ,tag'e in disposing the line Offlverlapping i a 40 oration. Lighter sandpapers, however, are more oblique relation to e T011, nd it also insures 40 subject to tearing, and, in speeding up the r t that all portions of the cover will be under tent o t 11, im in in t Way of secursion and will be supported circumferentially of jng proper balance become increasingly appamthe roll against the frictional drag of the WOlk, out. One of the problems that arises relates to as will later be more Particularly po nted out.

the securing of the abrasive covering to the ro'll M reover, covers of the form under considera- 45 in such a way as to minimize any tendency to n need? be su d at ativ ly few p nts tear, and by instrumentalities which comprise ag the frictional drag of the Work, by a minimum of moving parts likely to throw a minimizing the number of devices which ordihigh-speed roll out of balance. narily are required to secure abrasive covers to An object of the invention is to provide an their rolls and which render it diflicult to main- 50 improved rotary abrading tool embodying, among tain the rolls in proper balance at high speeds. other advantages, suitability for high speed These and other features of the invention will work. In accordance with this object, a feature be described as embodied in an illustrative mav of the inventionconsists in the combination of chine and pointedout in the appended claims.

an abrasive cover surrounding a tool body with Referring nowto the accompanying drawings,

Fig. 6 is a side elevation of the roll with a. yieldable support for the abrasive cover partly in' place roll without the abrasiveacoverf i Fig. 7 is a side elevation of, the completed:

Fig. 8 is an exploded perspective. view: of a" modified form of roll; and

Fig. 9 is a perspective view of. an abrasive.

cover for the roll shown in Fig. 8.

Referring to Figs. 1 and 2, a cylindrical drum or shell 16 which constitutes thefoundation of the roll body, has. rigidly 'secured to each end thereof, by screws (not-shown), ahead 12 which is in. the form. of an annular disk. Extending into the head v12 at the centralopening thereof is a sleeve 14 havingat, its outerend and beyond the ,end of the' druin loan annular flange 16. In the. flange 16 is formed a notch 18 to provide accessto a set screw 2 0..whereby the sleeve :14 maybe clamped to a shaft 22 upon which the abrading roll is to be mounted. In the illustrated roll the ;drum. 10, the head 12 and the sleeve 14are-all composed of aluminum, which,

because of its relative lightness, willtend to minimizethe vibration due to any slight lack of balance when the roll is rotated athigh speed.

Surroundingthe sleeve14; and filling up the space between the head 12 and the flange 16 is an annular disk of felt 24 having a diameter somewhat greater-than the external diameter of the drum 10. A shoulder 17 on the sleeve .14 abuts the head 12, and three screws 19 threaded into the head 12 and extending through the felt disk 24 and the flange 16 serve to hold the sleeve 14 in endwise clamping engagement with the head 12. Except as hereinafter noted, the construction of each end of the roll is like that of the other, and the description: of one end will be sufiicientb Referring to Fig. 6, a relatively narrow strip of paper 26 iswrapped helically about the drum 1() v and is pasted thereupon. Theends of the strip 26 are oblique, the strip being in the form of a rhomboid. These Oblique ends are disposed at such an an le as to cause them to abu't the felt disks 24 respectively when the paper strip 26 is in position upon the drum 1 0. Thesides of the paper strip 26 abut each other so as not to present ridges or depressions. Aftenthe paper strip 26 has thus been applied to .the drum 10, a strip 28 of' flannel of about the samesize and shape as the-paper strip 26 iswrapped helically upon. the paper strip 26in adirection opposite theretoand is pasted thereupon with its twosides abutting each other. .Upon the flannel strip 28 are wrapped successively aplurality of relativelywideflan-a nel strips; 30, about eight in number, of rhom boid form. The ,oblique ends of the flannel strips30 abut the felt disks 24 respectively, and the sides of each strip abut each other so. as not to leave, ridges ordepressions. The first flannel -strip 30 is wrapped helieally in adirection opposite to that of therelatively narrow flannel strip 28,; and each succeeding flannel/strip 36 is wrapped helically ina direction opposite to that of the strip immediately beneath it. The strips 30 may conveniently be applied by pasting with a latex cement first one end of each strip 30 to the strip immediately beneath it, then wrapping the strip 30 under moderate tension about the drum 10, and then similarly pasting the opposite end. After all of the strips 30 have thus been secured in position, they may be further secured at each end of the roll by stitching them to the felt disks 24 respectively. Such stitches .are shown at the left-hand end of the roll in "Figs. 6 and '7. The strips 28 and 30, in the illustrated roll, are of wool flannel, and they may advantageously be subjected to a partial shrinkingbefore applying them to the roll in order to give them the most desirable character and degree of resilience The roll body, when complete, will appear as shown in Fig. 7.

Surrounding the periphery of the roll body is an abrasive cover 32 having a V-shaped end 34 which is salient and an opposite V-shaped end .36 which is re-entrant, The sides of the abrasive cover 32 are straight and parallel to each other, and the ends 34 and 36 are so formed as to be parallel to each other when the abrasive cover 32 is stretched out flat and also when it is applied to a roll, as will be evident upon reference to Fig. 1. .The particular type of abrasive sheet material may be selected with reference to the character of the finishing or scouring operation to be performed. In the illustrated roll, for example, the cover 32 consists of a paper base with a glued surface covered with a grit composed of silicon carbide. At the vertex of the salient end 34 is formed a notch 38 the purpose of which is to receive a T-shaped clamping hook 40 for clamping this end of the abrasive cover against the roll body. The clamping hook 40 extends lengthwise with respect to the rolland is mounted at its central portion upon a stem 42. Adjacent to each end of the clamp member 40 is a rounded protuberance 44 to insure a positive gripping of the abrasive cover. The protuberances 44 may conveniently be obtained by. the use of rivets having rounded heads. The stem 42 is carried by a plunger 46 which reciprocates in a guideway 48 formed in a boss 50 of a carrier disk 52. The external diameter of the disk 52 is equal to the internal diameter of the drum l0, and the periphery of the disk 52 is flanged to accommodate screws 54 whereby the disk 52 is secured to the drum 10. An axial opening 56 is formed in the disk 52 to enable thelatter to clear the shaft 22, as shown in Fig. 2. The guideway 48 is substantially radial with respect to the roll body so that outward movement of the plunger 44 raises the flange 40 to facilitate the introduction of an abrading cover 32, and inward movement of the plunger 46 serves to bring the clamp 40 into operation to secure the end of the cover 32 to the roll body. To provide for actuation of the clamping mechanism a slot 58 (Fig. 4) is provided inthe plunger 40 and a cam roll 60 is mounted in the plunger 46, bridging the slot 58. An .-actuating rod 62 is disposed lengthwise of the roll and has an inclined cam surface 64 formed upon one of its ends for engaging the roll 60. Longitudinal movement of the rod 62 in one'direction will serve to urge the plunger 46 inwardly and to bring the clamp 40 into operation. A helical spring 66 is positioned between the plunger 46 and the base of the guideway .48 for, normally urging the clamp 40 outwardly. Another helical spring 68 surrounds inwardly inclined portion 118.

'the' rod 62 and is interposed'between a boss formed on the disk 52 and a pin 70 which is inserted in the rod 62. The spring 68 serves normally to urge the rod 62 toward unclamping position. The opposite end portion of the rod 62 extends through holes formed in the head 12, the felt disk 24, and the flange 16, respectively, this end of the rod 62 being rounded, as indicated at '76. The instrumentalities whereby reciprocation of the rod 62 may be effected will means of another and independently operable clamping device now to be described. Formed in each of the flanges 16 is a slot 78 which constitutes a guideway for a pair of clamping members 80 and 82. The slot 78 does not intersect the axis of the roll but is offset from it. In other words, the slot 78 is non-radial. The clamping member 80 is provided with. a clamping hook or vjaw 84 which extends substantially in a direction parallel to the axis of the roll body and which overlies the periphery of the. roll body. The member 80 is also provided. with an actuating stem 86 which is substantially parallel to the axis of the roll and which extends away from the end of the roll body. The clamping member 82 is shaped similarly to the clamping member 80 and underlies the clamping member 80. Its actuating stem is designated as 88. A rounded protuberance 89 is formed in the under surface of the clamping jaw 84 and registering therewith is a depression 91 formed in the jaw of the clamping member 82. The depression 91 may conveniently be formed by a stamping operation. The protuberance 89 and the depression 91 enable the clamping jaws to grip the abrasive cover firmly without punch ing a hole in it. o

Actuation of the clamp 40 and of the jaws 80 and 82 at one end of the roll body is effected'by 'means of a cam in the form of a disk mounted for rotation about the axis of the roll body. In order to facilitate registry of the cam 90 with the roll body, the sleeve 14 is provided with an annular flange 92 adapted to engage .a recess 94 formed in the cam 90. The cam 90 is held against axial movement relatively to the roll body by means of a screw 96 which extends through a slot 98 concentric with the. cam 90, the screw 96 being threaded into an opening 100 formed in the flange 16. A concentric groove 102 is formed in the cam 90 and in this groove is positioned a cam member of relatively hard steel having an inclined face 104 adjacent to one of its ends, the remaining operative portion .106 of the cam member presenting an inactive substantially radial face. Another cam groove 108 is formed in the cam disk 90."The cam groove 108 has a portion 110 which isconcentrio with the axis of the cam 90 and another portion 112 which inclines inwardly at a relatively sharp angle to the radius. A- third cam groove 114 is formed in the disk 90. The cam groove 114 has a concentric portion116 and an secured upon the end of the roll body, it is apparent that the rounded outer end 76 of the rod 62 will extend into the concentric -groove 102 this inclined face.

:the inner clamping member 82. actuating stem 88 of the inner clamping memthe jaws.

without engaging the inclined face 104, or possibly'zengaging the most depressed portion of The actuating stem 86 of theouterclamping member 80 will extend into theicam groove 108 and will be adjacent to the closed end of the concentric portion 110 thereof.

The actuating stem 88 of the inner clamping member 82 will extend into the cam slot 114 and will be adjacent to the closed end of the concentric portion 116 thereof. Upon rotation of the cam disk 90 the'inclined face 104- will force the actuatingrod 62 toward the left, as viewed .in Fig. 2, causing the clamp 40 to be drawn inwardly to clamping position. Upon further rotation of the cam disk 90 the inactive surface 106 of the cam member will ride upon the end of the rod 62 and thus maintain the clamp 40 in clamping position. As the cam 90 is thus further rotated, the actuating stem 86 of the clamp 80 will engage the inclined portion 112 of the cam groove 108, causing the clamping jaw 84 to be drawn inwardly until it clamps the abrasive cover against the corresponding jaw of Thereupon the her 82 will engage the inclined portion 118 of the cam slot 114, and both of the clamping jaws will be drawn down with the abrasive cover :gripped between them. It is desirable to provide for clearance between the actuating stems 86 and 88 and the sides of their respective cam slots, leaving a certain amount of play or lostmotion to each of, the clamping members. To insure gripping of the abrasive cover notwithstanding such lost-motion, the flange 16 is bored I to receive a compression spring 79, the bore constituting, in ,effect, an extension of the slot 78., The spring 79 urges the inner clamping ,member 82 outwardly as far as permitted by the cam slot 114, causing the inner clamping member 82 to grip the abrasive cover resiliently against the outer clamping member 80. The jaws of the clamping members 80-and 82 (Fig. 6) extend over the periphery of the felt disks 2 4, but they are not long enough to extend over 1 the drum 10 and the flannel covering, so that the drum 10 and the relatively thin flannel covering will not interfere with the retraction of The felt disks 24 are notched at their peripheries as indicated at 25, but the notches are not deep enough to accommodate the full retraction of the clamping jaws, so that when the jaws are fully retracted to secure the abrasive cover, the disks 24 will be under compression and will thus-assist the springs 79 in resiliently supporting the lower clamping jaw against the pressure of the upper clamping jaw.

-When the jaws are fully retracted, they are within the periphery of the roll. The'cam disk 90 at the left-hand end of the roll is in all rethe weight of the material so as to insure proper balance.

In applying the abrasive cover 32 to the roll,

'the operator first fits the recess 38' of the abrasive cover about the stem 42 of the central clamping device and rotates the' right-hand cam disk. 90 snificientlyito .bring the clamp -40 down. firmly into: clamping position The salientend of the abrasive cover thus :beingdfirrnly secured to the roll bo.dy,.the operator tucks the edges of the abrasive cover under the .jaws of the lower, clamping mem'bers 82, and he then wraps the abrasive cover about the :rollxand .tensions it about :the: roll; as tightly as the" can. Power .is, of. course-shut oil from the machine at this time, and the shaft 22 'may :beulocked against rotation to holdit against the pull of the operator upon the abrasive coven-x-Hethen inserts theborriers of' 'the re-entrant end of the abrasive cover between the jaws ofthe clamping members and .82.. Upon further rotation of the right-hand cam disk andupon rotation of the left-hand cam disk 90 the jaws of the clamping members grip between them the abrasive :coverand also,- by.r.eason1of the nonradial dispositionof the slots '78, they pull the re-entrant end of the abrasive :cover in a direction having a circumferential component, thereby further. tensioning the abrasive cover. Furthermore, the under surfaces of the jaws of the lower clamping members 82 grip the edges of the abrasive cover adjacent to the salient end thereof.

In Fig. 8 is shown a modified form of roll which; difier's from the above-described form only in certain particulars which will now be pointed out. The body structure of themodifled form of roll is substantially the same as that of the roll illustrated in Fig. 1. The'central..clamping member, however, is .omitted in the form of roll now under consideration. In this form of roll the end flanges 16" are provided with radial slots 178 which constitute guideways for inner and outer clamping members and 182 which are similar to the clamping members 80 and 82, respectively, the clamping member 180 :being provided with an actuating stem 186 and the clamping member 182 being provided with an actuating stem 188. A eam disk 190, which is similar to the cam disk .90 except for the omission of the slot 98 and the groove 102, is provid'edfor actuating the clamping members 180 and 182. The oam disk has formed in it a cam groove 208 and a cam slot .2l4 respectively. Both of these cam elements are spir al in relation to the axis of the cam disk, the groove 208 at its outer end portion .300 being more sharply inclined outwardly than the remaining portion of this groove. The cam disk 190 is held against axial movement away from thefiange 16 by means of :a screw 302 which extends'through the cam slot 214 andlis threaded into the actuating stem 188, a washer 304 being provided to prevent the cam disk from slipping off. The cam disks 190 at each end of the roll body are identical except for the fact that the cam slots in one of them extendin reverse spirals with respect to the other. This arrangement affords the convenience of enabling both cam disks. to be turned in the same direction to effect clamping or unclamping. An abrasive cover 132 having a salient end-1 34 and a re-entrant end 136 is provided for this form of ,roll. No notch is provided at the vertex of the salient vend of the cover 132 but the margin 206 of the under surface of the salient end is coated with adhesive for a purpose which will appear as the description proceeds. The margin 207 of the outer surface of the re-entrant end 136 is also coated :withan adhesive. ,{Ifhe abrasive cover 132 is applied upon the roll illustratedin Fig. 8' by first inserting. thecorners of the re-entrant and between the clamping members 180 and 182 at each end of the roll body. Upon rotation of the cam disks 190 the outerclamping member 180 is retracted more rapidly than the inner clamping member 182 by .reason of the fact that the end portion 300 of the cam groove 208 is more sharply inclined than the corresponding portion of the cam slot 214. This causes the clamping jaws to close, and further movement of the cam disk 190 serves to embed the clamping jaws into the felt disk 24." The re-entrant end of the cover 132 now being securelyclamped upon the roll body, the operator Wraps the abrasive cover about the roll body with as much tension as he can and, aftermoistening the adhesive-covered margins 206 and 207, he presses the salient end of the abrasive cover firmly down and pastes it upon the re-entrant end. The adhesive upon the margins 206 and 207 may be glue of a character similar to that of the glue which holds the grit uponthe. abrasive cover, enabling the various layers of glue to coalesce and form an effective bond between the overlapping edges of the paper. It will be notedthat the abrasive covers 32 and 132 are both perforated as indicated at 210. The purpose of this is to enable air which has been entrapped beneath the cover to escape as the work presses down upon the cover.. This. avoids any likelihood of the entrapped air bulging the cover in advance of the work. The perforations 210 also permit air to enter immediately after each portion of the roll passes the work. By thus eliminating the effects of air pressure, they enable the flannel covering above described to exert its natural resilience. Perforations are especially desirable in a cover such as .thelcover 32 which is adapted to be clamped at the vertex of its salient end, for in the absence of such perforations the clamping of the cover at this point would tend to prevent the retreat of an air pocket and the hard pocketioficompressed air would result in a bumpingeffect upon the work.

The advantages in the use of a cover having salient and re-entrant ends in combination with cover-securing devices of the type above described are several. In the first place, they enable the line of discontinuity between the two ends of the abrasive cover to be presented obliquely to the work, thereby avoiding .such shock as would result from the line of discontinuity striking squarely against the work. In

the second place, they enable the pull occasioned by the drag of the work against the abrading surface to be transmitted obliquely to the clamp 40, as in the form disclosed in Fig. 1, and to the clamping devices 180 and 182, as in the form shown in Fig. 8; both of these forms that there is no portion of the abrasive coverbut what is able to transmit its portion of the drag of the work to its clamping devices in a direction which has a circumferentialcomponent. In other words, no por-.

It is thus apparent in 1,984,480 constitute a very effective means for taking up the drag occasioned} by the work, andthereby reinforcing the cover by enabling it to withstand this drag, and thereby eliminating any tendency The overlapped end136,

of the cover to bulge. while it does not function as an'abradingsur face, does functiodtogether with the adhesive on the margn'206, as a reinforcing member to transmit the drag of the work directly to the clamps jand 182. Because of the V shape of this reinforcing member, the drag of the work will set up a direct tension initrather than a stress tending to twist or distort the cover.

Having described my invention, what I claim said abrasive cover to said roll body, a clamp for securing in position the opposite end of I said abrasive cover, and operating means for said clamps constructed and arranged to enable one end of the abrasive cover to be clamped in position independently of the other end.

2. An abrading tool comprising a tool body,

an abrasive cover surrounding said tool body with one end of said abrasive cover secured in overlapping relation to the other end, and a T-shaped 'clamp'overlapping the working surface of the tool body and covered by the overlapping end of the abrasive cover for clamping the overlapped endof the abrasive cover to said tool body.

3. An abrading r011 comprising a roll body, an abrasive cover or sheet material surrounding said roll body and having V-shaped ends which are respectively salient and re-entrant, a hook for clamping the vertex of the salient end of said abrasive cover against said roll body, and": means for securing the side corners of the reentrant end of said abrasive cover to said r011 body with the re-entrant end overlapping the salient end and covering said hook.

4. In an abrading roll, a roll body, a pair of clamping hooks extending over the periphery of said roll body adjacent to the ends respectively of the roll body for securing one end of an abrasive cover, and a third hook carried by said r011 body at a point spaced a substantial distance lengthwise and circumferentially of said roll body from the two first-mentioned clamping hooks for clamping the other end of the abrasive cover against the periphery of the roll body.

5. In an abrading roll, a roll body, a plurality of clamping devices displaced from each other both axially and circumferentially with respect to said roll body for securing an abrasive cover to said roll body, and means constructed and arranged to operate said clamping devices in succession.

6. In an abrading roll, a roll body, a clamping device disposed between the ends of said roll body for securing a portion of an abrasive cover to said roll body, a clamping device disposed adjacent to one end of said roll body for securing another portion of the abrasive cover to said roll body, and mechanism including a cam constructed and arranged upon relative rotation with respect to said roll body to operate said clamping devices in succession.

7; In an abrading rolLfa roll body,'a clamping: device disposed midway between'the ends of said roll body'for' securing the mid-portion of one end ofan abrasive cover to said roll body, a pair of clamping devices disposed aqjaeem, to the ends respectively of said "rollbody for se-, curing the corners off-the opposite-end oithe abrasive cover to 'said"roll'jbody,- mechanism including a cam constructed and arranged upon relative rotation with respect'tosaid roll body first to operate the firstmentioned clamping d6 vice'and then to operate-one ofthe end-clamp ing devices, and means for operating the otherend-clampilfls device.- r 7 f 8. In air-abrading roll, 'a' roll body," a clamping hook-for securing an abrasive cover upon said roll body, a spring normally'urg'ingsaidclamping'hookputwardly from saidroll body to facilitate the insertionpf the abrasive cover, and means including a wedge constructed and arranged by lengthwisemovem'ent with respect to said roll body to move'said clamping position. i

9.'In an abrading rolL-a roll: body, a clamping hook for securing an abrasive cover upon said roll body, mechanism including a" rod extending lengthwise of said rollbody for operating said clamping hook, and a cam-constructed andarrangeduponrelative rotation with respect to said roll body to move said rod longitudinally to operate said clamping hook. I a 7 10. In a rotary'abrading toolf-a tool'bod'y having a yieldable periphery, a 'clamping hook extending 'over the periphery 'of said tool body for securing an abrasive cover upon said too'lbody,

and means for moving said-clamping hook ina direction having bothinward and tangential components relatively to said tool body to cause said clamping hook to grip and tension the abrasive cover.

ing a yieldable periphery,-a pair of clamping jaws extending over the periphery "of said tool body for securingan abra'sive cover upon said tool body, means for closing said "clamping jaws to grip the abrasive cover between "them andior yieldable peripheryfiofs'aid tool=body.

12. In a rotary abrading tool, a tool body, a pair of clamping jaws for securing an abrasive cover upon said tool body, and means including a pair of cam elements operable respectively upon said clamping jaws to effect a relative closing movement of said jaws to grip the abrasive cover and to move said jaws both inwardly and circumferentially with respect to said tool body to tension the abrasive cover.

13. In a rotary abrading tool, a tool body, a pair of clamping jaws extending over the periphery of said tool body, an abrasive cover surrounding said tool body, said abrasive cover at a point adjacent to one of its ends extending between one of said clamping jaws and the periphery of said tool body, said abrasive cover also at a point adjacent to its opposite end extending between said clamping jaws, and means for closing and retracting said clamping jaws to clamp said opposite end portion of the abrasive cover between them and to clamp the firstmentioned end against the periphery of the tool body.

14. In a rotary abrading tool, a tool body having a guideway extending inwardly in a direction ofiset from the axis of said tool body, a pair of clamping members slidable in said guidedrawing said clamping jaws inwardly against the hook inwardly to v having an inwardly extending guideway, a pair.

of. clamping members slidable in said guideway for securing an abrasive cover upon said tool body, and a cam constructed and arranged first to eifect a relative clamping movement of said clamping members and then to draw said clamping members. inwardly.

16. In a rotary abrading tool, a tool body having. a guideway extending inwardly in a direction offset from the axis of said tool body, a pair of clamping members slidable insaid guideway for securing. an abrasive cover upon said tool body, and'a cam constructed and arranged first to effect a relative clamping movement of said clamping members togrip the abrasive cover and then to draw said clamping members inwardly to tension the abrasive cover.

1.7. In a rotary abrading tool, a tool body, a pair of members mounted in said tool bodyconstructed and arranged to clamp between them an abrasive cover for the tool body, and a cam mounted for relative rotation. with respect to said tool body, said cam having a pair of slots which are engaged by said clamping members respectively and which are shaped to cause relative closing of saidv clamping members.

18. In a rotary abrading tool, a tool body, a pair of members mounted in said tool body constructed and arranged to clamp between them an abrasive cover for the tool body, and a cam mounted for relative rotation with respect to said tool body, said cam. having, a pair of slots which are engaged by said clamping members respectively and which are shaped to cause said clamping members first to grip a portion of the abrasive cover and then to draw the gripped portion of the abrasive cover inwardly with respect to said tool body as the cam is rotated,

roll body, a. relatively thick felt cover at each of the ends of the roll body; said core having a relatively greater diameter beneath said flannel cover and a relatively less diameter beneath. said felt covers, the external diameters of said flannel and felt covers being substantially equal, anda clamping hook. at each end of the roll body extending over the adjacent felt cover for clamping an abrasivecover upon the roll body.

20.: Ina rotary abrading tool, a tool body having a rigid core, a yieldable cover for said core of relatively shallow depth and terminating short of the ends of said core, a yieldable cover of relatively greater depth adjacent to each end of said core, and clamping devices positioned adjacent to each end of said core: and movable inwardly for securing an abrasive cover upon said roll body, said devices being adapted when in clamping position to lie within the peripheries of said coversof relatively greater depth respectively.

21. A rotary abrading tool comprising a tool body, an abrasive cover wrapped around said tool body with the endsof the abrasive cover pasted together in overlapping relation, and means: covered by the overlapping end, of said abrasive cover for securing the overlapped end to said tool body.

. 22. An abrading roll comprising a roll body, an,.-abrasive cover wrapped around said roll body with the ends of the abrasive cover pasted together in overlapping relation, and clamping devices adjacent respectively to each end of said roll body for securing the overlapped end of said abrasive cover to saidroll body, said clamping devices being covered by the overlapping end of said abrasive cover.

23. An abrading roll comprising a roll body, an abrasive cover of sheet material surroundingsaid roll body, said cover having V-shaped ends which are respectively salient and reentrant, clamps, extending over the peripheral surface of the roll body for securing the two corners of. the re-entrant end of said covering to said roll body, and adhesive means for securing together the ends of said cover.

WILLIAM A. REED. 

